SCAGRIDER22: I was just on Unilocks website and noticed the same thing about the Umbriano, but I noticed that they also note the following:
Jointing Material and Joint Stabilization
∑ Good: Ordinary dry joint sand
∑ Better: Most polymeric sands can be used (proper cleaning is essential prior to and during activation)
∑ Best: ordinary dry joint sand stabilized by a water-based or solvent based joint sand stabilizer sealer.
I have laid 3 patios recently with Umbriano and used poly in the joints with good results.